1. Field of the Invention
The present invention relates to a hermetic compressor, and more particularly to a supercharging device of the hermetic compressor capable of supplying a great deal of refrigerant into a cylinder.
2. Description of the Related Art
Generally, a hermetic compressor is widely used for compressing refrigerant in a freezing apparatus such as a refrigerator.
As shown in FIG. 1, a reciprocating compressor as one of the hermetic compressors comprises an electric driving unit and a compressing unit. The compressing unit is used for compressing the refrigerant by being driven by the electric driving unit in a sealed casing 1.
The electric driving unit comprises a stator 10, a rotor 20 for being rotated by an electromagnetic interaction with the stator 10, and a crankshaft 21 installed at a center of the rotor 20.
The compressing unit comprises a cylinder block 40, a connecting rod 31 eccentrically connected with a lower part of the crankshaft 21, a piston 32 that linearly reciprocates in a cylinder 41 formed in the cylinder block 40 by being connected with a front end of the connecting rod 31, and a cylinder head 43 for sealing the cylinder 41. A valve assembly 42 is disposed between the cylinder head 43 and the cylinder 41. The valve assembly 42 includes a suction valve (not shown) and a discharge valve (not shown) for controlling a flow of the refrigerant between the cylinder head 43 and the cylinder 41.
A suction muffler 50, connected with one side of the cylinder head 43, is disposed at an upper part of the cylinder head 43. A refrigerant suction pipe 51, for drawing in the refrigerant from an evaporator (not shown) of the freezing apparatus, is connected with the suction muffler 50. On the other hand, a discharge muffler 60, connected with the other side of the cylinder head 43, is disposed at a lower side of the cylinder block 40.
For a compressor having the above construction, since the piston 32 reciprocates between an upper dead point and a lower dead point in the cylinder 41 by a rotation of the crankshaft 21, the refrigerant is drawn into the cylinder 41 and discharged to outside of the cylinder 41 after being compressed. In other words, the refrigerant is drawn into the cylinder head 43 after orderly passing through the evaporator, the suction pipe 51 and the suction muffler 50. When the suction valve (not shown) formed at the valve assembly 42 is opened, the refrigerant is drawn into the cylinder 41. After that, when the discharge valve (not shown) is opened, the refrigerant compressed in the cylinder 41 is discharged to the cylinder head 43, and flows to a condenser (not shown) of the freezing apparatus through the discharge muffler 60.
However, for the reciprocating compressor with the above construction, a general amount of the refrigerant drawn into the cylinder is only 60 to 70% compared to an amount of the refrigerant discharged by the piston 32. In other words, in a conventional reciprocating compressor, volume efficiency is 60 to 70%. The low volume efficiency is due to leakage of the refrigerant between the valve assembly 42 and the cylinder 41 and between the piston 32 and the cylinder 41, clearance volume formed between an upper end of the piston 32 and the valve assembly 42 when the piston reaches the upper dead point, and expansion of the refrigerant by the temperature inside of the cylinder 41.
When the volume efficiency is low, the compressing efficiency of the compressor is also low, thus the volume efficiency should be increased for a compressor with a high efficiency.
The present invention has been made to overcome the above-mentioned problems of the related art. Accordingly, it is an object of the present invention to provide a supercharging device of a hermetic compressor capable of increasing a volume efficiency by drawing in a great deal of refrigerant to a cylinder.
The above object of the present invention is accomplished by providing a super charging device of a hermetic compressor comprising a suction chamber connected with a refrigerant suction pipe and the cylinder, wherein the suction chamber is formed at one side of a cylinder block; a suction fan rotatably disposed in the suction chamber for being rotated in accordance with a rotation of a crankshaft; and transmitting means for transmitting the rotation force of the crankshaft to the suction fan.
Here, the transmitting means comprises a driving pulley formed on the crankshaft; a driven pulley formed on a rotating shaft of the suction fan; and a belt connecting the driving pulley and the driven pulley. Alternatively, the transmitting means can comprise a driving gear formed on the crankshaft; a driven gear formed on the rotating shaft of the suction fan; and an idle gear connecting the driving gear and the driven gear.
On the other hand, the suction chamber comprises a cylindric body protruded from a lower side of the cylinder block and a semi-spherical cover for shielding the body.
According to the supercharging device of the present invention, since the suction fan is rotated by being connected with the crankshaft, and transmits the refrigerant of the suction chamber, the amount of the refrigerant drawn into the cylinder is increased, and consequently, the volume efficiency of the compressor is increased.